Outline

We recorded auditory brainstem and cognitive responses to study the central auditory processes in 14 healthy persons (they have normal hearing) and 10 patients suffered from central nervous system disease (sclerosis multiplex). We performed BAEP investigations using 14 different frequency of stimuli (10-64 Hz) and cognitive ERP investigations using acoustic oddball paradigm under active condition: the stimuli consisted of 1000 Hz frequent and 2000 Hz deviant (20 % sequental probability) stimuli presented in pseudorandom order with a fixed interstimulus interval of 1 s.

We conclude that increasing the stimulus rate the latencies of each BAEP–peaks and interpeak latencies become longer and the amplitudes decreased. In case of patients suffered from central nervous system diseases these disturbances were more definite. The most definite changes could be seen in case of latencies of IV/V. waves. The normal BAEP examinations could be expanded with these forced increase of the frequency of stimuli. Our results shows that the problems of central nervous system influence the waveform of cognitive event-related potential components including MMN, N2b and P300. The amplitudes was decreased and the latencies was increased in patients’ group compared with control group. The difference was most definit in the case of P300 component. Finally we suggest that the BAEP examinations using different frequency of stimuli and cognitive ERP examinations could be a useful method in differential diagnosis of the central nervous system diseases.